Hi

As far as I'm aware, the nominative plural of the two nouns медвед and сосед are медведи and соседи. I am wondering why. They are both hard masculine nouns, and neither are affected by any of the spelling rules, so, they should theoretically end in -ы, right?

Are there any other common nouns that do this? Could it be that nouns ending in -ед just end in -и in the nominative plural, for no particular reason? I don't know, just a suggestion. Maybe it's a relic of an old plural form from Old Church Slavonic, or something like that?

Thanks
Jack